The effect of dopamine on muscle PO2 in healthy volunteers and intensive care patients.

The effect of systemic dopamine administration (2-10 micrograms kg-1 min-1) on the Po2 distribution (histograms) and the mean Po2 in the m. vastus lateralis of m. quadriceps femoris in nine healthy volunteers and seven critically ill patients has been studied with a newly developed bedside measuring procedure. Dopamine initially raised mean muscular Po2 in both groups. In the volunteers, mean muscular Po2 thereafter decreased gradually but still remained slightly elevated after 30 min of dopamine infusion. This increase in muscle oxygenation could be abolished by the administration of a dopamine antagonist (metoclopramide). In the patients, the initial dopamine-induced increase of Po2 was significantly slower and reached a plateau within 30 min. The results are discussed with special attention given to the data available on the action of dopamine on given peripheral circulation.